def ground_clearance(self):
# returns ground clearance based on current leg positions
# legs are attached to a top surface of thorax
# as leg Z in thorax cs is negative when foot is below thorax, ground clearance is assumed to be (max leg Z) - (thorax height)
THORAX_HEIGHT = m(48)
z_list = []
for leg in self.legs.values():
if not leg.in_swing: # only legs in stance are considered
z_list.append(leg.get_node("foot-thorax").z) # get coordinates of all feet in thorax cs
if len(z_list) > 0:
return -1 * max(z_list) - THORAX_HEIGHT
else:
return 0 # this generally should not happen, unless hex is flying
def __init__(self, name, parent, mount_descriptor, servo_ids):
global COXA_LENGTH, FEMUR_LENGTH, TIBIA_LENGTH, TARSUS_LENGTH
self.name = name
self.parent = parent
self.mount_descriptor = mount_descriptor
self.swing_order = 0 # used to keep track of the order in which legs swing. If two legs are ready to swing, priority is given to the one that has been in stance longer
self.r_was_increasing = False # indicates whether restrictedness of this leg was increasing before reaching flat plateau
self.cs = CoordinateSystem(parent.cs, self.name, mount_descriptor.x, mount_descriptor.y, mount_descriptor.z, 0, 0, mount_descriptor.rotz)
self.segments = dict()
self.segments["coxa"] = Segment(name=name + "_coxa", servo_id=servo_ids[0],
min_angle=r(-35), neutral_angle=r(0), max_angle=r(35),
length=COXA_LENGTH, parent=self,
leg=self,
offset_in_parent=m(0), mirrored=(mount_descriptor.x < 0), z_rot=True)
if self.name == "rf":
self.segments["coxa"].max_angle = r(10)
elif self.name == "lf":
self.segments["coxa"].min_angle = r(-10)
elif self.name == "rr":
self.segments["coxa"].min_angle = r(-10)
elif self.name == "lr":
self.segments["coxa"].max_angle = r(10)
self.segments["femur"] = Segment(name=name + "_femur", servo_id=servo_ids[1],
min_angle=r(-45), neutral_angle=r(20), max_angle=r(90), length=FEMUR_LENGTH,
parent=self.segments["coxa"], leg=self,
offset_in_parent=COXA_LENGTH)
self.segments["tibia"] = Segment(name=name + "_tibia", servo_id=servo_ids[2],
min_angle=r(-115), neutral_angle=r(20), max_angle=r(20), length=TIBIA_LENGTH,
parent=self.segments["femur"], leg=self,
offset_in_parent=FEMUR_LENGTH)
self.segments["tarsus"] = Segment(name=name + "_tarsus", servo_id=servo_ids[3],
min_angle=r(-90), neutral_angle=r(0), max_angle=r(0), length=TARSUS_LENGTH,
parent=self.segments["tibia"], leg=self,
offset_in_parent=TIBIA_LENGTH)
self.rostral_neighbor = None # leg in front
self.caudal_neighbor = None # leg behind
self.in_swing = False # is this leg in swing
self.swing_z = 0 # target highest Z of current swing (calculated as Z of lift-off point + DEFAULT_SWING_HEIGHT), all in thorax cs
self.touched_down = False # whether the leg actually touches ground
self.wants_to_swing = False # previously the leg wanted to swing, but was not allowed to do it
self.landing = False # leg is forced to land
self.raising = False # leg is in initial phase of swing
coxa_seg = self.segments["coxa"]
self.home_angle = (coxa_seg.min_angle + coxa_seg.max_angle) / 2
self.home_position_leg = Position(self.cs)
self.home_position_thorax = Position(self.cs.parent)
self.task_cs = CoordinateSystem(parent.cs, self.name + "_tcs", 0, 0, 0, 0, 0, 0)
self.swings_inwards = False # foot swings towards thorax
self._r_ws_inner = None # restrictedness by inner edge of foot workspace
self._r_ws_outer = None # restrictedness by outer edge of foot workspace
# stored previous values of restrictedness components
self._r_coxa_prev = 0
self._r_femur_prev = 0
self._r_tibia_prev = 0
self._r_tarsus_prev = 0
self._r_stretch_prev = 0
self._r_contract_prev = 0
self._r_ws_outer_prev = 0
self._r_ws_inner_prev = 0
self._r_prev = 0 # previous total restrictedness
# back-ups for angles and leg node positions
self.angles_backup = StoredAngles(0, 0, 0, 0)
self.nodes_backup = dict()
self.stored_node_positions = dict() # already calculated coordinates of leg nodes
# coxa coordinates in leg cs and thorax cs never change
self.stored_node_positions["coxa"] = Position(self.cs, 0, 0, 0)
self.stored_node_positions["coxa-thorax"] = self.cs.parent.to_this(self.stored_node_positions["coxa"])
def fill_legs(self):
# initializes legs and puts them in a dictionary
# leg mount point is on the top surface of thorax
self.legs["rf"] = Leg("rf", self, MountDescriptor(m(+182.343), m(-104.843), m(0), r(-045.0)), (101, 102, 103, 19))
self.legs["rm"] = Leg("rm", self, MountDescriptor(m(0000.000), m(-114.198), m(0), r(-90.00)), (104, 105, 106, 11))
self.legs["rr"] = Leg("rr", self, MountDescriptor(m(-182.343), m(-084.843), m(0), r(-135.0)), (107, 108, 109, 14))
self.legs["lf"] = Leg("lf", self, MountDescriptor(m(+182.343), m(+104.843), m(0), r(+045.0)), (116, 117, 118, 13))
self.legs["lm"] = Leg("lm", self, MountDescriptor(m(0000.000), m(+114.198), m(0), r(+90.00)), (113, 114, 115, 20))
self.legs["lr"] = Leg("lr", self, MountDescriptor(m(+182.343), m(+084.843), m(0), r(+135.0)), (110, 111, 112, 15))
self.legs["rf"].rostral_neighbor = self.legs["lf"]
self.legs["rf"].caudal_neighbor = self.legs["rm"]
self.legs["rm"].rostral_neighbor = self.legs["rf"]
self.legs["rm"].caudal_neighbor = self.legs["rr"]
self.legs["rr"].rostral_neighbor = self.legs["rm"]
self.legs["rr"].caudal_neighbor = self.legs["lr"]
self.legs["lf"].rostral_neighbor = self.legs["rf"]
self.legs["lf"].caudal_neighbor = self.legs["lm"]
self.legs["lm"].rostral_neighbor = self.legs["lf"]
self.legs["lm"].caudal_neighbor = self.legs["lr"]
self.legs["lr"].rostral_neighbor = self.legs["lm"]
self.legs["lr"].caudal_neighbor = self.legs["rr"]
class Leg(object):
COXA_LENGTH = m(42.8)
FEMUR_LENGTH = m(70)
TIBIA_LENGTH = m(67.5)
TARSUS_LENGTH = m(71.3)
INNER_WS_LIMIT = m(COXA_LENGTH + 70)
OUTER_WS_LIMIT = m(165)
def __init__(self, name, parent, mount_descriptor, servo_ids):
global COXA_LENGTH, FEMUR_LENGTH, TIBIA_LENGTH, TARSUS_LENGTH
self.name = name
self.parent = parent
self.mount_descriptor = mount_descriptor
self.swing_order = 0 # used to keep track of the order in which legs swing. If two legs are ready to swing, priority is given to the one that has been in stance longer
self.r_was_increasing = False # indicates whether restrictedness of this leg was increasing before reaching flat plateau
self.cs = CoordinateSystem(parent.cs, self.name, mount_descriptor.x, mount_descriptor.y, mount_descriptor.z, 0, 0, mount_descriptor.rotz)
self.segments = dict()
self.segments["coxa"] = Segment(name=name + "_coxa", servo_id=servo_ids[0],
min_angle=r(-35), neutral_angle=r(0), max_angle=r(35),
length=COXA_LENGTH, parent=self,
leg=self,
offset_in_parent=m(0), mirrored=(mount_descriptor.x < 0), z_rot=True)
if self.name == "rf":
self.segments["coxa"].max_angle = r(10)
elif self.name == "lf":
self.segments["coxa"].min_angle = r(-10)
elif self.name == "rr":
self.segments["coxa"].min_angle = r(-10)
elif self.name == "lr":
self.segments["coxa"].max_angle = r(10)
self.segments["femur"] = Segment(name=name + "_femur", servo_id=servo_ids[1],
min_angle=r(-45), neutral_angle=r(20), max_angle=r(90), length=FEMUR_LENGTH,
parent=self.segments["coxa"], leg=self,
offset_in_parent=COXA_LENGTH)
self.segments["tibia"] = Segment(name=name + "_tibia", servo_id=servo_ids[2],
min_angle=r(-115), neutral_angle=r(20), max_angle=r(20), length=TIBIA_LENGTH,
parent=self.segments["femur"], leg=self,
offset_in_parent=FEMUR_LENGTH)
self.segments["tarsus"] = Segment(name=name + "_tarsus", servo_id=servo_ids[3],
min_angle=r(-90), neutral_angle=r(0), max_angle=r(0), length=TARSUS_LENGTH,
parent=self.segments["tibia"], leg=self,
offset_in_parent=TIBIA_LENGTH)
self.rostral_neighbor = None # leg in front
self.caudal_neighbor = None # leg behind
self.in_swing = False # is this leg in swing
self.swing_z = 0 # target highest Z of current swing (calculated as Z of lift-off point + DEFAULT_SWING_HEIGHT), all in thorax cs
self.touched_down = False # whether the leg actually touches ground
self.wants_to_swing = False # previously the leg wanted to swing, but was not allowed to do it
self.landing = False # leg is forced to land
self.raising = False # leg is in initial phase of swing
coxa_seg = self.segments["coxa"]
self.home_angle = (coxa_seg.min_angle + coxa_seg.max_angle) / 2
self.home_position_leg = Position(self.cs)
self.home_position_thorax = Position(self.cs.parent)
self.task_cs = CoordinateSystem(parent.cs, self.name + "_tcs", 0, 0, 0, 0, 0, 0)
self.swings_inwards = False # foot swings towards thorax
self._r_ws_inner = None # restrictedness by inner edge of foot workspace
self._r_ws_outer = None # restrictedness by outer edge of foot workspace
# stored previous values of restrictedness components
self._r_coxa_prev = 0
self._r_femur_prev = 0
self._r_tibia_prev = 0
self._r_tarsus_prev = 0
self._r_stretch_prev = 0
self._r_contract_prev = 0
self._r_ws_outer_prev = 0
self._r_ws_inner_prev = 0
self._r_prev = 0 # previous total restrictedness
# back-ups for angles and leg node positions
self.angles_backup = StoredAngles(0, 0, 0, 0)
self.nodes_backup = dict()
self.stored_node_positions = dict() # already calculated coordinates of leg nodes
# coxa coordinates in leg cs and thorax cs never change
self.stored_node_positions["coxa"] = Position(self.cs, 0, 0, 0)
self.stored_node_positions["coxa-thorax"] = self.cs.parent.to_this(self.stored_node_positions["coxa"])
def __str__(self):
return self.name
def update_swings_inwards(self):
# Indicates whether the swing movement is towards inner limit of workspace
coxa = self.get_node("coxa")
current_foot = self.get_node("foot")
moved_foot = current_foot.clone
moved_foot.x += .0001 * sind(-1 * self.task_cs.rotz)
moved_foot.y += .0001 * cosd(-1 * self.task_cs.rotz)
self.swings_inwards = coxa.distance_to(current_foot) > coxa.distance_to(moved_foot)
@property
def joint_angles(self):
# return joint angles as tuple
segment_coxa = self.segments["coxa"]
segment_femur = self.segments["femur"]
segment_tibia = self.segments["tibia"]
segment_tarsus = self.segments["tarsus"]
coxa = segment_coxa.current_angle
femur = segment_femur.current_angle
tibia = segment_tibia.current_angle
tarsus = segment_tarsus.current_angle
return coxa, femur, tibia, tarsus
def set_joint_angles(self, coxa, femur, tibia, tarsus):
# set joint angles with tuple
segment_coxa = self.segments["coxa"]
segment_femur = self.segments["femur"]
segment_tibia = self.segments["tibia"]
segment_tarsus = self.segments["tarsus"]
segment_coxa.current_angle = coxa
segment_femur.current_angle = femur
segment_tibia.current_angle = tibia
segment_tarsus.current_angle = tarsus
self.stored_node_positions.clear()
self._r_ws_inner = None
self._r_ws_outer = None
def store_node(self, name):
# noinspection PyShadowingNames
def x_y(l, coxa_angle):
x = l * sind(-coxa_angle)
y = l * cosd(-coxa_angle)
return x, y
if name == "foot":
segment_coxa = self.segments["coxa"]
coxa_len = segment_coxa.length
coxa_angle = segment_coxa.current_angle
segment_femur = self.segments["femur"]
femur_angle = segment_femur.current_angle
femur_projection_h = segment_femur.length * cosd(femur_angle)
femur_projection_v = segment_femur.length * sind(femur_angle)
segment_tibia = self.segments["tibia"]
tibia_angle = segment_tibia.current_angle
tibia_projection_h = segment_tibia.length * cosd(femur_angle + tibia_angle)
tibia_projection_v = segment_tibia.length * sind(femur_angle + tibia_angle)
segment_tarsus = self.segments["tarsus"]
tarsus_angle = segment_tarsus.current_angle
tarsus_projection_h = segment_tarsus.length * sind(90 + (tibia_angle + femur_angle + tarsus_angle) - 180)
tarsus_projection_v = segment_tarsus.length * cosd(90 + (tibia_angle + femur_angle + tarsus_angle) - 180)
l = coxa_len + femur_projection_h + tibia_projection_h + tarsus_projection_h
z = femur_projection_v + tibia_projection_v + tarsus_projection_v
x, y = x_y(l, coxa_angle)
node_pos_converted = Position(self.cs)
node_pos_converted.x, node_pos_converted.y, node_pos_converted.z = x, y, z
elif name == "foot-odom":
foot_thorax = self.get_node("foot-thorax")
node_pos_converted = self.cs.parent.parent.to_this(foot_thorax)
elif name == "coxa-thorax":
segment_coxa = self.segments["coxa"]
node_pos = Position(segment_coxa.cs)
node_pos_converted = self.cs.parent.to_this(node_pos)
elif name == "foot-thorax":
foot = self.get_node("foot")
node_pos_converted = self.cs.parent.to_this(foot)
elif name == "tibia-thorax":
segment_coxa = self.segments["coxa"]
coxa_len = segment_coxa.length
coxa_angle = segment_coxa.current_angle
segment_femur = self.segments["femur"]
femur_angle = segment_femur.current_angle
femur_projection_h = segment_femur.length * cosd(femur_angle)
femur_projection_v = segment_femur.length * sind(femur_angle)
l = coxa_len + femur_projection_h
z = femur_projection_v
x, y = x_y(l, coxa_angle)
node_pos_converted = Position(self.cs)
node_pos_converted.x, node_pos_converted.y, node_pos_converted.z = x, y, z
else:
node_pos = Position(self.segments[name].cs)
node_pos_converted = self.cs.to_this(node_pos)
self.stored_node_positions[name] = node_pos_converted
return node_pos_converted
def get_node(self, name):
try:
return self.stored_node_positions[name]
except:
return self.store_node(name)
def store_foot_odom(self, foot_thorax=None):
if foot_thorax is None:
self.stored_node_positions["foot-odom"] = self.cs.parent.parent.to_this(self.get_node("foot"))
else:
self.stored_node_positions["foot-odom"] = foot_thorax.owner.parent.to_this(foot_thorax)
def calc_joint_angles(self, target_position, best_effort):
general_calculation = True
position_leg_cs = self.cs.to_this(target_position)
angle_coxa = -1 * d(atan2(position_leg_cs.x, position_leg_cs.y))
femur_to_position_projection = 0
femur_segment = self.segments["femur"]
femur_length = femur_segment.length
tibia_segment = self.segments["tibia"]
tibia_length = tibia_segment.length
tarsus_segment = self.segments["tarsus"]
tarsus_length = tarsus_segment.length
coxa_segment = self.segments["coxa"]
if best_effort:
tgt_tarsus = position_leg_cs.clone
tgt_tarsus.z += tarsus_length
femur = self.get_node("femur")
# check if we can actually reach target_position
distance = femur.distance_to(tgt_tarsus)
max_dist = femur_length + tibia_length
min_dist = third_side(femur_length, tibia_length, 180 + tibia_segment.min_angle)
dz = femur.z - tgt_tarsus.z
# are we too far?
if distance > max_dist:
# yep, too far
# calculate femur angle to target
femur_to_position_projection = sqrt(max_dist ** 2 - dz ** 2)
general_calculation = False
elif distance < min_dist:
# we are too close
femur_to_position_projection = sqrt(min_dist ** 2 - dz ** 2)
general_calculation = False
else:
# we are not too close and not too far
general_calculation = True
if general_calculation:
# works either when not best_effort or when best_effort and distance is ok
coxa_to_position_projection = sqrt(position_leg_cs.x ** 2 + position_leg_cs.y ** 2)
femur_to_position_projection = coxa_to_position_projection - coxa_segment.length
distance_to_tarsus_top = sqrt(femur_to_position_projection ** 2 + (position_leg_cs.z + tarsus_length) ** 2)
if position_leg_cs.z + tarsus_length == 0:
angle_down_to_tarsus_top = 0
else:
angle_down_to_tarsus_top = 90 - angle_ab(-1 * (position_leg_cs.z + tarsus_length), distance_to_tarsus_top, femur_to_position_projection)
angle_femur = angle_ab(femur_length, distance_to_tarsus_top, tibia_length) - angle_down_to_tarsus_top
angle_tibia = -180 + angle_ac(femur_length, distance_to_tarsus_top, tibia_length)
angle_tarsus = -180 + 90 - angle_femur - angle_tibia
if coxa_segment.min_angle > angle_coxa:
if best_effort:
angle_coxa = coxa_segment.min_angle
else:
raise Exception(self.name + " coxa angle too low")
elif coxa_segment.max_angle < angle_coxa:
if best_effort:
angle_coxa = coxa_segment.max_angle
else:
raise Exception(self.name + " coxa angle too high")
if femur_segment.min_angle > angle_femur:
if best_effort:
angle_femur = femur_segment.min_angle
else:
raise Exception(self.name + " femur angle too low")
elif femur_segment.max_angle < angle_femur:
if best_effort:
angle_femur = femur_segment.max_angle
else:
raise Exception(self.name + " femur angle too high")
if tibia_segment.min_angle > angle_tibia:
if best_effort:
angle_tibia = tibia_segment.min_angle
else:
raise Exception(self.name + " tibia angle too low")
elif tibia_segment.max_angle < angle_tibia:
if best_effort:
angle_tibia = tibia_segment.max_angle
else:
raise Exception(self.name + " tibia angle too high")
if tarsus_segment.min_angle > angle_tarsus:
if best_effort:
angle_tarsus = tarsus_segment.min_angle
else:
raise Exception(self.name + " tarsus angle too low")
elif tarsus_segment.max_angle < angle_tarsus:
if best_effort:
angle_tarsus = tarsus_segment.max_angle
else:
raise Exception(self.name + " tarsus angle too high")
return angle_coxa, angle_femur, angle_tibia, angle_tarsus
def backup(self):
# stores current joint angles so that they could be restored
self.angles_backup = StoredAngles(self.segments["coxa"].current_angle, self.segments["femur"].current_angle, self.segments["tibia"].current_angle, self.segments["tarsus"].current_angle)
self.nodes_backup = dict()
for node_name in self.stored_node_positions:
self.nodes_backup[node_name] = self.stored_node_positions[node_name]
def rollback(self):
# restores joint angles to what is stored
self.set_joint_angles(self.angles_backup.coxa, self.angles_backup.femur, self.angles_backup.tibia, self.angles_backup.tarsus)
self.stored_node_positions = self.nodes_backup
def update_home_position(self):
h_dist_home = (Leg.OUTER_WS_LIMIT + Leg.INNER_WS_LIMIT) / 2
roll_dist_home = h_dist_home * cosd(self.cs.roty)
self.home_position_leg = Position(self.cs, roll_dist_home * sind(-self.home_angle), roll_dist_home * cosd(-self.home_angle), 0)
self.home_position_leg.z = -38
self.home_position_thorax = self.cs.parent.to_this(self.home_position_leg)
return self.home_position_leg
def redefine_task_cs(self, translate_x, translate_y, rotate_z):
if not (translate_x == 0 and translate_y == 0 and rotate_z == 0):
# calculate movement vector angle
current_foot_pos_thorax = self.get_node("foot-thorax")
odom_cs = self.cs.parent.parent # leg->thorax->odom
foot_pos_odom = odom_cs.to_this(current_foot_pos_thorax)
moved_thorax_cs = self.cs.parent.get_derivative("tmp_thorax_for_tcs_vector", translate_x, translate_y, 0, 0, 0, rotate_z)
new_foot_pos_thorax = moved_thorax_cs.to_this(foot_pos_odom, caller="redefine_task_cs")
dx = new_foot_pos_thorax.x - current_foot_pos_thorax.x
dy = new_foot_pos_thorax.y - current_foot_pos_thorax.y
angle = d(atan2(dx, dy)) - 180
home_pos = self.home_position_thorax
self.task_cs.redefine_tuple(home_pos.tuple, (None, None, -angle))
self.update_swings_inwards()
else:
self.swings_inwards = None
@property
def anterior_neighbor(self):
angle = self.task_cs.rotz
if -90 < angle < 90:
return self.rostral_neighbor
else:
return self.caudal_neighbor
@property
def posterior_neighbor(self):
angle = self.task_cs.rotz
if -90 < angle < 90:
return self.caudal_neighbor
else:
return self.rostral_neighbor
@property
def can_swing(self):
return not self.caudal_neighbor.in_swing and not self.rostral_neighbor.in_swing
# RESTRICTEDNESS -->
def store_r(self):
# store restrictedness components
self._r_coxa_prev = self.r_coxa
self._r_femur_prev = self.r_femur
self._r_tibia_prev = self.r_tibia
self._r_tarsus_prev = self.r_tarsus
self._r_ws_inner_prev = self.r_ws_inner("store_r/")
self._r_ws_outer_prev = self.r_ws_outer("store_r/")
self._r_stretch_prev = self.r_stretch
self._r_contract_prev = self.r_contract
self._r_prev = self.r()
@property
def r_ws_inner(self):
if self.r_ws_inner is None:
self.update_r_ws()
return self._r_ws_inner
@property
def r_ws_outer(self):
if self.r_ws_outer is None:
self.update_r_ws()
return self._r_ws_outer
@property
def r_coxa(self):
lower_limit = self.segments["coxa"].min_angle
upper_limit = self.segments["coxa"].max_angle
transition_zone = 20
parameter = self.segments["coxa"].current_angle
return exp_r(parameter, lower_limit, upper_limit, transition_zone)
@property
def r_femur(self):
lower_limit = self.segments["femur"].min_angle
upper_limit = self.segments["femur"].max_angle
transition_zone = 10
parameter = self.segments["femur"].current_angle
return exp_r(parameter, lower_limit, upper_limit, transition_zone)
@property
def r_tibia(self):
lower_limit = self.segments["tibia"].min_angle
upper_limit = self.segments["tibia"].max_angle
transition_zone = 10
parameter = self.segments["tibia"].current_angle
return exp_r(parameter, lower_limit, upper_limit, transition_zone)
@property
def r_tarsus(self):
lower_limit = self.segments["tarsus"].min_angle
upper_limit = self.segments["tarsus"].max_angle
transition_zone = 10
parameter = self.segments["tarsus"].current_angle
return exp_r(parameter, lower_limit, upper_limit, transition_zone)
def update_r_ws(self):
# changes either when thorax CS is redefined (body moved) or when this leg is moved
foot_position_odom = self.cs.parent.parent.to_this(self.get_node("foot-thorax")) # leg->thorax->odom
coxa_position_odom = self.cs.parent.parent.to_this(self.get_node("coxa-thorax")) # leg->thorax->odom
foot_position_odom.z = 0
coxa_position_odom.z = 0
transition_zone = 10
parameter = coxa_position_odom.distance_to(foot_position_odom)
lower_limit = Leg.INNER_WS_LIMIT
upper_limit = 100000000
self._r_ws_inner = exp_r(parameter, lower_limit, upper_limit, transition_zone)
lower_limit = -100000000
upper_limit = Leg.OUTER_WS_LIMIT
self._r_ws_outer = exp_r(parameter, lower_limit, upper_limit, transition_zone)
@property
def r_ws(self):
if self.in_swing:
if self.swings_inwards:
return self.r_ws_inner()
else:
return self.r_ws_outer()
else:
return self.r_ws_outer() + self.r_ws_inner()
@property
def r_stretch(self):
lower_limit = -100000000
upper_limit = (self.segments["femur"].length + self.segments["tibia"].length) * 0.9
transition_zone = 5
try:
tarsus = self.stored_node_positions["tarsus"]
except:
tarsus = self.store_node("tarsus")
try:
femur = self.stored_node_positions["femur"]
except:
femur = self.store_node("femur")
parameter = femur.distance_to(tarsus)
return exp_r(parameter, lower_limit, upper_limit, transition_zone)
@property
def r_contract(self):
lower_limit = third_side(self.segments["femur"].length, self.segments["tibia"].length, 180 + self.segments["tibia"].min_angle)
upper_limit = 100000000
transition_zone = 20
try:
tarsus = self.stored_node_positions["tarsus"]
except:
tarsus = self.store_node("tarsus")
try:
femur = self.stored_node_positions["femur"]
except:
femur = self.store_node("femur")
parameter = femur.distance_to(tarsus)
return exp_r(parameter, lower_limit, upper_limit, transition_zone)
def r_stance(self):
return max(self.r_coxa, self.r_femur, self.r_tibia, self.r_tarsus, self.r_ws)
@property
def r_swing(self):
# in most cases growing r_coxa indicates final phase of swing
# in a case when task_cs is exactly aligned with leg cs, r_coxa will be constant throughout swing, so alternative criterion is needed
result = 0
# is task_cs aligned with leg cs?
tcs_angle = 0 + self.task_cs.rotz
if tcs_angle > 180:
tcs_angle -= 360
if abs(tcs_angle - self.cs.rotz) < 0.0001:
r_stretch = self.r_stretch
if r_stretch > self._r_stretch_prev + 0.0001:
result = max(self.r_tarsus, r_stretch)
elif abs(tcs_angle + self.cs.rotz) < 0.0001:
r_contract = self.r_contract
if r_contract > self._r_contract_prev + 0.0001:
result = max(self.r_tibia, r_contract)
else:
# use growing r_coxa as final swing indicator
r_coxa = self.r_coxa
if r_coxa > self._r_coxa_prev + 0.0001:
r_stretch = self.r_stretch
if r_stretch <= self._r_stretch_prev:
r_stretch = 0
# r += max(r_coxa, self.r_tarsus, self.r_stretch)#, self.r_ws("r_swing"))
if self.raising:
r_tarsus = 0
else:
r_tarsus = self.r_tarsus
result = max(r_coxa, r_tarsus, r_stretch)
else:
result = 0
return result
def r(self):
if self.in_swing:
return self.r_swing
else:
return self.r_stance()
def r_change_direction(self, test_r=None):
# returns 1 when restrictedness is increasing, 2 -- when decreasing, 0 -- when restrictedness is constant
# if test_r is provided, previous restrictedness is compared to this test_r, otherwise -- to current leg restrictedness
if test_r is None:
new_r = self.r
else:
new_r = test_r
if new_r > self._r_prev + 0.0001:
return 1
elif new_r < self._r_prev - 0.0001:
return -1
else:
return 0